1. Field of the Invention
This invention relates to a device and method for effectively treating dysphagia. In particular, the present invention relates to a device and method for treating dysphagia by providing simultaneous electrical stimulation to the facial and pharyngeal regions on an afflicted person.
2. Description of the Related Art
Dysphagia is the inability of difficulty in swallowing and may be caused by stroke, neurodegenerative diseases, or a respiratory disorder. Swallowing is a complicated action which is usually initiated voluntarily but always completed reflexively, whereby food is moved from the mouth through the pharynx and esophagus to the stomach. The act of swallowing occurs in three stages and requires the integrated action of the respiratory center and motor functions of multiple cranial nerves, and the coordination of the autonomic system within the esophagus.
In the first stage, food is placed on the surface of the tongue. The tip of the tongue is placed against the hard palate. Elevation of the larynx and backward movement of the tongue forces the food through the isthmus of the fauces in the pharynx. In the second stage, the food passes through the pharynx. This involves constriction of the walls of the pharynx, backward bending of the epiglottis, and an upward and forward movement of the larynx and trachea. Food is kept from entering the nasal cavity by elevation of the soft palate and from entering the larynx by closure of the glottis and backward inclination of the epiglottis. During this stage, respiratory movements are inhibited by reflex. In the third stage, food moves down the esophagus and into the stomach. This, movement is accomplished by momentum from the second stage, peristaltic contractions, and gravity. Although the main function of swallowing is the propulsion of food from the mouth into the stomach, swallowing also serves as a protective reflex for the upper respiratory tract by removing particles trapped in the nasopharynx and oropharynx, returning materials refluxed from the stomach into the pharynx, or removing particles propelled from the upper respiratory tract into the pharynx. Therefore, the absence of adequate swallowing reflex greatly increases the chance of pulmonary aspiration.
In the past, exclusive electrical stimulation of the throat to treat dysphagia has been used and is disclosed by the inventor in U.S. Pat. Nos. 6,104,958 and 5,987,359, and now incorporated by reference herein. While is it known that a person is unable to swallow while his or her mouth is open, what is needed is a device that simultaneously electrically stimulates both the facial and pharyngeal regions of the head to promote swallowing.